With a reflection of the U.S. Capitol dome serving as a backdrop, Texas Sen. Ted Cruz reacts to a question about negative perceptions of Tea Party Republicans during the Reuters Washington Summit in Washington, Oct. 24, 2013. (REUTERS/Jim Bourg)

Arguably, the most effective advocate of this theory has been Slate’s Dave Weigel, who has sought to dispel incorrect “conventional wisdom” about how tea party candidates have cost the GOP seats.

For example, after running through the numbers of the various Senate elections since 2010, Weigel concludes:

I’d say you can only blame “the Tea Party” for a net loss of two Senate seats since 2010. That’s a period during which it helped send Mike Lee, Ron Johnson, Pat Toomey, Marco Rubio, Ted Cruz, and Rand Paul to the upper House—during which “establishment” candidates like Denny Rehberg, Heather Wilson, Rick Berg, Josh Mandel, George Allen, Tommy Thompson, Carly Fiorina, and Dino Rossi totally failed to win seats.

A few obvious points …

1). If getting some of these fresh, young conservatives elected was a tradeoff, then I’d say the GOP came out ahead of the game.

2). Clearly the notion that “establishment” candidates always — or even usually — fare better in General Elections is a fallacy.

3). Weigel doesn’t get into this, but it’s worth mentioning that sometimes primary challenges can make a difference — even when the challenger loses. My guess is that fending-off (and ultimately crushing) Matt Bevin’s candidacy might have actually helped Mitch McConnell, while also serving to make him a better conservative vote.